Finite density lattice QCD - Challenge for the sign problem and the first principle calculation of the high density system

2015 Fiscal Year Final Research Report

• Project/Area Number: 24340054
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Osaka University (2015); Hiroshima University (2012-2014)
• Principal Investigator: Nakamura Atsushi 大阪大学, 核物理研究センター, 協同研究員 (30130876)
• Co-Investigator(Kenkyū-buntansha): Kunihiro Teiji 京都大学, 理学研究科, 教授 (20153314) ; Hatsuda Tetsuo 独立行政法人理化学研究所, 仁科加速器研究センター, 主任研究員 (20192700) ; Ohnishi Akira 京都大学, 基礎物理学研究所, 教授 (70250412)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: QCD / 符号問題 / 数値シミュレーション / 高密度状態 / 相構造 / Lee Yangゼロ / 閉じこめ / モンテカルロ計算

Outline of Final Research Achievements

In order to study QCD phase structure, the lattice QCD simulation is most reliable since it is a first principle calculation. However, the lattice QCD at finite density suffers from so-called sign problem. So far, there have been many progresses as Taylor expansion, imaginary chemical potential method and multi-parameter re-weighting, but still it is difficult to reach low temperature and high density regions.
To go further, we have developed a canonical approach constructed from the fugacity expansion in this project. We have constructed also a method to construct the canonical partition functions from experimental data assuming only the particle anti-particle symmetry. We can now relate experimental data and lattice simulation at finite density regions.

Free Research Field

原子核理論